Secret-keyhole latch.



I. DI BELLA. I sncnm KEYHOLE LATCH. APPLICATION FILED OUT. 12, 1908.

Patnted Apr. 6,-1909.

I am. E 8

Z w r M1444 Z 6 a MW 2 w u n4: Nonms pzrsns' 01., WASHINGTON, n. c.

saint FRANK DI BELLA, OF NEW YORK, N. Y.

SECRET-ICE] YHOLE LATCH.

Application filed October 12, 1908.

Specification of Letters Eatent.

Patented April 6, 1909.

S erial No. 457,346.

To all whom 'it may concern:

Be it known that I, FRANK DI BELLA, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Secret- Keyhole Latches; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to secret key hole latches or secret escutcheon plates.

The object of the invention is to provide a device of this character which will absolutely prevent any unauthorized tampering with the lock.

A further object of the invention is to provide a secret escutcheon or key hole plate which will be cheap to manufacture and adapted to be applied to all cylinder locks of the class shown in diagram in the drawings.

With these and other objects in view, the invention consists of certain novel features of construction, combination and arrangement of parts, as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings, Figure 1 is a front elevation of the device applied to a door, Fig. 2 is a similar elevation with the lid open, some of the parts being shown in section, Fig. 3 is a horizontal section taken on the line 33 of Fig. 1 with the lock shown in full lines, Fig. 4 is a vertical sec tion taken on the line 4-4 of Fig. 1.

Referring more especially to the drawings, 1 represents the door, 2 the lock and 3 the cylinder thereof, which in this instance is surrounded by a collar 4, formed integral with the escutcheon casing 53. The collar 4; passes through an aperture 6, formed in the door and is held therein by a threaded annular clamp nut 7, which engages the lower end thereof and seats in an annular recess 8, formed around the aperture 6.

The casing 5 comprises a bottom plate 9 secured to the cylinder 4 and three raised sides 10, 11 and 12, which are integral with each other and permanently secured to the base. The remaining side 13 is hollow and has a plurality of slots adapted to receive the guiding and retaining lugs 14 and 15, the latter being at the forward end of the casing and adapted to bear against the spiral spring 16, Whose opposite end is held against a bridge piece 17. Carried by the sliding side 13 is a latch member 18, which engages the notched stud 19, carried upon the lid 20. This lid is hinged to the side member 12 as at 21, and is provided with a leaf spring 22, adapted to bear against the bottom 9 of the casing and raise the lid when released by the catch 18. As the side 13 presents an appearance similar to the side 11, and as the joint is made exceptionally close fitting it is impossible to tell which of the two move, or that they move at all, and unless a person is familiar with the lock it will be impossible to detect the means of opening the lid 20.

In operation, the side 13 is pressed downwardly releasing the catch 18 from the stud 19 and allowing the spring 22 to force the lid to a slightly raised position when it may be lifted and the key inserted in the block cylinder 3.

In order to prevent the device from turning in the aperture 6 I provide a plurality of pointed lugs 23, which are adapted to enter the front piece of the door 1 and hold the casing in position thereon.

From the foregoing description, taken in connection with the accompanying drawings, the construction and operation of the invention will be readily understood without requiring a more extended explanation.

Various changes in the form, proportion and the minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of this invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An escutcheon plate comprising a casing, a lid for covering said casing, and a movable side on the casing comprising in part means to lock said lid.

An escutcheon plate comprising a casing, a lid pivoted to said casing, and means forming a part of said casing and constituting in part a secret lock for the lid.

3. An escutcheon plate comprising casing having three integral sides, a lid pivoted to one of said sides, a sliding side, a latch carried by said sliding side, stud carried by the lid for engagement with the latch, and means for holding the sliding side with the latch normally in engagement with the stud.

4. An escutcheon plate comprising a casing, a lid therefor, a movable side on the eas- 1 side to engage the lug to lock the lid in closed position, and a spring positioned between the easing and side to normally hold the same in looking position.

In testimony whereof I have hereunto set my hand in presence of tWo subscribing Witnesses.

FRANK DI BELLA. Witnesses: v

FREDERICK C. LANBANNETT. ANDREA Dr SoHo. 

